code: def log_failure_event(
      self, kwargs, response_obj, start_time, end_time
  ):
      print(f"On Failure")
      self.failure = True
  
file_path: litellm/litellm/tests/test_configs/custom_callbacks.py
imports: from litellm.integrations.custom_logger import CustomLogger
  import inspect
  import litellm
label_desc: Use image node_id 6 for calling the testCustomCallbackProxy obj's underlying member method code with example usage: obj.log_failure_event(kwargs, response_obj, start_time, end_time) without return types